CVE-2026-68746 Livebook Teams identity check fails open when the deployment group is unresolvable, allowing unauthenticated access
Unauthenticated attackers can gain full access to Livebook servers if the deployment group cache becomes unresolvable, bypassing identity enforcement.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68746?
CVE-2026-68746 is a high-severity authentication bypass vulnerability in livebook-dev livebook, published on 5 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Not Failing Securely ('Failing Open') vulnerability in livebook-dev livebook allows an unauthenticated network client to obtain full access to a Livebook server that enforces identity through Livebook Teams.
A Livebook Agent or App Server connected to Livebook Teams caches the identifier of the deployment group it belongs to, and resolves that identifier against a locally cached list of deployment groups on every request in order to decide whether Teams identity enforcement is active. Livebook.Hubs.TeamClient.handle_call/3 in lib/livebook/hubs/team_client.ex does not distinguish a deployment group that could not be resolved from one that was resolved with identity enforcement switched off: the clause matches only the case where a group was found with enforcement enabled, and falls through to a catch-all that reports enforcement as switched off for everything else. The two neighbouring functions that decide user and application access resolve the same identifier and treat the same unresolved result as a denial.
When the identity status is reported as switched off, Livebook.ZTA.LivebookTeams.authenticate/3 in lib/livebook/zta/livebook_teams.ex returns empty identity metadata and allows the request to continue instead of halting it. LivebookWeb.UserPlug.build_current_user/3 merges that empty metadata into a newly built user, whose access type defaults to full access, and LivebookWeb.AuthPlug.authorized?/1 grants access to any user holding full access.
The cached identifier becomes unresolvable when the deployment group it refers to is deleted while the agent is not connected to receive the change, most concretely when a deployment group is deleted during the window in which an agent is disconnected or reconnecting. The client removes the group from its cached list without clearing the identifier that refers to it. Any client able to reach the affected server over the network is then granted the same access as a fully privileged member of the organisation, including the ability to read notebooks and configured secrets, execute code on the server's runtime, and disrupt its operation.
This issue affects livebook: from 0.19.7 before 0.19.9.
Weakness: CWE-636
Which versions are affected by CVE-2026-68746?
1 open source package ship an affected version, including livebook. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
livebook Hex | From 0.19.7 | 0.19.9 |
Products include Livebook Livebook.
How do I fix CVE-2026-68746?
Upgrade livebook to 0.19.9 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-68746 being exploited?
There is no known exploitation of CVE-2026-68746 in the wild and no public exploit code.
Other vulnerabilities in livebook-dev livebook
- CVE-2026-66298 JS-view sandboxed output can synthesize keyboard events to trigger unconfirmed global shortcuts
- CVE-2023-35174 Livebook Desktop's protocol handler can be exploited to execute arbitrary command on Windows
- CVE-2026-66881 Path traversal in imported file_entries name allows arbitrary file write via URL-type entry download
- CVE-2026-66885 Livebook Teams identity callback lacks state binding, allowing login CSRF
- CVE-2026-66297 Unescaped deployment environment variables in generated setup commands
Sources
Also known as EEF-CVE-2026-68746, GHSA-74j5-6grg-g6wj.